Makefile: link builtins residing in bin directory to main git binary too

To conserve space/improve file caching we try to make hard or symbolic links
from each builtin program to the main git executable rather than having
each be a complete duplicate copy of it.  We weren't doing this for the
builtin programs residing in the bin directory though.  So, let's do so.

Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -2079,6 +2079,12 @@ endif
 		test -z "$(NO_CROSS_DIRECTORY_HARDLINKS)" && \
 		ln "$$bindir/git$X" "$$execdir/git$X" 2>/dev/null || \
 		cp "$$bindir/git$X" "$$execdir/git$X"; } ; } && \
+	for p in $(filter $(install_bindir_programs),$(BUILT_INS)); do \
+		$(RM) "$$bindir/$$p" && \
+		ln "$$bindir/git$X" "$$bindir/$$p" 2>/dev/null || \
+		ln -s "git$X" "$$bindir/$$p" 2>/dev/null || \
+		cp "$$bindir/git$X" "$$bindir/$$p" || exit; \
+	done && \
 	for p in $(BUILT_INS); do \
 		$(RM) "$$execdir/$$p" && \
 		ln "$$execdir/git$X" "$$execdir/$$p" 2>/dev/null || \